Part 1 – Does Reforestation Contribute to Global Warming?

As counterintuitive as the concept may seem, there is a growing number of environmentalist that believe that reforestation is a contributor to Global Warming. Eco Preservation Society has been researching this issue and will present a series of articles on the topic. In this series of articles we will explore the issues around Reforestation, Carbon Offsets and Albedo Effect.

We would also like to invite all of those interested in this subject to join our ongoing discussion at Treehugger.com .

The first article in this series comes from Mathew Feldman at the Carbon Neutral Digest and lays the groundwork for discussion. The second article will deal more closely with understanding Aldedo Effect and its importance to this discussion.

Trees

Planting trees is the most common way to offset carbon production and is the most controversial. The theory is that one tree over the lifetime of that tree destroy one ton of carbon dioxide.

Here are just a few problems with that theory. What is the lifetime of a tree? Will it take 75 years to remove a ton of carbon? Will it take 100 years to remove a ton of carbon?

A 2005 Lawrence Livermore National Laboratory(LLNL) study using climate models examined the effectiveness of planting trees in different areas as a way to offset carbon production. What they found was nothing less shocking, snow is white and reflects heat. Trees are not white and absorb more heat then snow, hence heating the earth up. As the earth gets hotter more snow melts, more trees grow making the earth even hotter. You can see were this is going. LLNL ran simulation models comparing trees versus shrubs/grassland. Trees were shown to make the earth 1.6 C warmer when planted and grasslands were shown to make the earth cooler by 0.38C. So why would anyone plant trees as a carbon offset project?

There are some exceptions to this idea. The first exception is planting trees in the Amazon rain forest. The idea is that the rainforest works in a synergy and adding more trees to this synergy is beneficial. The other exception is planting trees in an urban area. Trees are cooler then pavement, and will provide a cooling effect to the pavement.

The Australia Institute also took a look at tree planting as an offset project. They found some rather interesting results. The first issue is that forestry projects cannot permanently store carbon. At some point the forest will be cut down or burned, when that happens the stored carbon is released into the environment. The forest soil can hold a vast sums of carbon from decaying leaves, trees, and branches. When the forest is cut down or burned the soil can release that carbon into the environment.

Tree planting can lead to carbon leakage. When trees are planted on land, the land use changes. If the land was being used for farms, houses, or recreational activities people may just clear new land and continue those activities. Where this happens, the apparent emission reductions from a forestry projects could ‘leak’ out of another forest area.

Climate change will have an impact of forestry offsets. With the current environmental change caused by global warming rain fall levels are not the same. Many tree planting offset projects are happening in areas that might not have enough rain to support a forest.